1. Field of the Invention
The present invention generally relates to pneumatic devices. More specifically, the present invention relates to pneumatic transfer systems.
2. Description of the Prior Art
Many different types of businesses have turned to drive through type customer interface systems in order to make doing business more convenient for the customer and more cost effective for businesses. Most of these business transactions can be performed by way of a pneumatic transfer system that employs a carrier sized and shaped to fit within a conduit that extends from a sending and receiving station within the building where the business is located to a sending and receiving station outside of the building positioned so that a customer can easily make a transaction via the pneumatic transfer system while sitting inside a motor vehicle. Several of these systems that exist in the prior art are disclosed here.
U.S. Pat. No. 6,164,491 issued to Bustos et al. discloses a pneumatic product vending and delivery system preferably using an existing product vending machine as a storage and loading device for use in a pneumatic vending and delivery system along with an interface unit in place of the vending machine door. A product dispensing terminal is provided that is connected by the delivery tube of a pneumatic conveyor from the storage and loading device, which has a loading mechanism configured to load a product dispensed by the dispensing mechanism into the delivery tube. The pneumatic conveyor includes a back pressure source operable to apply reverse pressure to a product in the delivery tube to gently slow a product approaching the product dispensing terminal through the tube.
U.S. Pat. No. 4,059,246 issued to Anders et al. discloses a pneumatic tube system for conducting banking transactions with a non-captive carrier traveling between a bank teller terminal in a two-tube carrier conveyor connected with a remote customer terminal with visual communication between the teller and the customer. The operation of a blower located at the customer terminal, which supplies air for pressure or vacuum movement of the carrier in the two system, is controlled by carrier arrival at or dispatch from either terminal.
U.S. Pat. No. 6,146,057 issued to Gromley discloses a pneumatic transfer apparatus that utilizes a pair of centrally located blowers to create a pressure differential within the system.
U.S. Pat. No. 4,180,354 issued to Greene discloses a pneumatic transmission system adapted to send a carrier from one terminal to a second terminal with apparatus to control the free delivery of the carrier to a terminal comprising a check valve to relieve pressure behind a carrier once it has passed a check valve and an adjustable air valve to control the negative pressure ahead of the carrier to control the free delivery of the carrier from the end of the transmission tube in a single tube reversing system with negligible amount of air being taken into or discharged from the open terminal.
U.S. Pat. No. 5,215,412 issued to Rogoff discloses a pneumatic transport system, particularly useful as a mail transport system, which includes a transport carrier moving through a pneumatic tube line between remote sending/receiving stations is described. Movement of the transport carrier through the pneumatic tube line is by means of a positive or negative air flow in the tube line provided by a blower means. The air flow direction is controlled by utilizing a series of adjustable valves, such as butterfly valves. The system additionally employs sensors for indicating the presence of the carrier in the exterior station.
Many of these types of systems have been employed for many years and have become expensive to maintain as they have aged. An alternative to the expensive proposition of constantly repairing a worn out system is needed. The claimed invention provides a pneumatic shifter device that can be used as a retrofit to an existing system that eliminates the cycle of repairing a worn out system. The claimed invention also provides a pneumatic shifter device that can be installed in a newly constructed pneumatic transfer system that may be maintained more easily and more cost effectively.